Mail_fetcher socket error

Hi,
I am using the mail_fetcher from

rubyforge.org/var/svn/slantwise/fetcher

as described in Advanced Rails Recipes,
Recipe 40.

It works great, but every once in a while
I get a SocketError and it dies with the
error output:

./script/…/config/…/vendor/plugins/fetcher/lib/fetcher/…/vendor/secure_pop.rb
:98:in initialize': getaddrinfo: Name or service not known (SocketError) from ./script/../config/../vendor/plugins/fetcher/lib/fetcher/../vendor/ secure_pop.rb:98:in do_start’
from /usr/lib/ruby/1.8/timeout.rb:56:in timeout' from /usr/lib/ruby/1.8/timeout.rb:76:in timeout’
from
./script/…/config/…/vendor/plugins/fetcher/lib/fetcher/…/vendor/
secure_pop.rb:98:in do_start' from /usr/lib/ruby/1.8/net/pop.rb:432:in start’
from
./script/…/config/…/vendor/plugins/fetcher/lib/fetcher/pop.rb:21:
in establish_connection' from ./script/../config/../vendor/plugins/fetcher/lib/fetcher/base.rb:31 :in fetch’
from script/mail_fetcher:16:in start' from script/mail_fetcher:15:in start’
from ./script/…/config/…/lib/daemon.rb:55:in start' from ./script/../config/../lib/daemon.rb:45:in start’
from ./script/…/config/…/lib/daemon.rb:32:in daemonize' from ./script/../config/../lib/daemon.rb:14:in daemonize’
from script/mail_fetcher:27

Does anyone know what causes this error?

Thanks,

Jim